Molding press



MOLDING PRESS Filed March 21, 1941' 12 Sheets-Sheet 1 IEE.

uU M- m a uw n u v |||||||1|| 4 A .M 9 U 4 0 0 0 2 M r 2 4 9 M I 0 0 0 00 0 0 M 4 w n Ew t PAUL E. flowens P. E. FLOWERS Feb. 6, 1945.

MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet 2 u g NEE F I 5 0 O OC V O O n 3 Q2 Feb. 6, 1945.

P. E. FLOWERS MOLDING PRES S Filed March 21, 1941 12 Sheets-Sheet 3INVENTON PAUL E. FLOWERS,

Feb. 6, 1945. P. E. FLOWERS MOLDING PRESS Filed March 21, 1941 12Sheets-Sheet 4 .Jmm PAUL [.Flowms,

Womags Feb. 6, 1945. P FLOWERS 2,368,756

MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet 5 [8? JfEao /2al 2 JA/I 2,30 :20 [Vans 1E5. I m 7/ 72 i um 5 9 s Xh v Wily 1, i1!

I I l Jrwwm PAUL E. FLOWERS,

cbtomys Feb 6, 1945. P. E. FLOWERS 2,368,756

MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet 6 Feb. 6, 1945. E,FLOWERS 2,368,756

MOLDING PRESS Filed March 21 1941 12 Sheets-Sheet 7 1 Jmm 3yAULEFLOWERS, CA)! 2 alt/W Feb. 6, 1945. P. E. FLOWERS MOLDING PRESS 194112 Sheets-Sheet 8 Filed March 21 JJTiE'l.

TIME

Feb. 6, 1945.

P. E. FLOWERS MOLDING PRESS Filed March 2]., 1941 12 Sheets-Sheet 9 BwLE. FL owERS, P t x Feb. 6, 1945.

P. E. FLOWERS MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet 10Paul. E. FLOWERS,

Feb. 6, 1945. FLOWERS 2,368,756

MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet 11 Feb. 6, 1945.

P. E. FLOWERS MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet l2 a;uvu 2: mm. mow mm oQu on.

wmm 15 w N0 w L. OF N 5 mm A m w a MMw LH @aiiented Felto 3945 STATESPATENT OFFICE MOLDING PRESS Paul E. Flowers Mount Gilead, Ohio, assignorto The Hydraulic Development Corporation, line Wilmington, Del, acorporation of Delaware Application March 21, 1941, Serial No. 384,520v

l3 @lalms. (Cl. 18-16) for causing the latter first to carry out amolding stroke and thereafter an ejecting stroke.

It is another object to provide a molding press of typeset forth in thepreceding paragraph, in which the molding plunger carries out aretraction stroke immediately preceding the electstroke, and in whichthe said retraction stroke is shorter than the molding stroke oitheplunger.

Another object oi the invention consists in the provision of a presswith a hydraulically operable press platen, in which a pressure fluidsource for supplying pressure to actuate said platen is mechanicallycontrolled by the latter so as to cause the platen to carry out only apartial retraction stroke following the pressing stroke and thereafterto perform an ejecting stroke and a complete return stroke.

It is a further object to provide a molding press comprising a diecarrier, in which mechanical means is adapted, in vresponse to thetravel of the press plunger, selectively to initiate movement'of saiddie carrier into or out of alignment with said press plunger. I

' A still further object of the invention consists in the provision of apress as mentioned in the preceding paragraph, in which the operationof' hydraulically operable means for reciprocating the die carrier ismechanically controlled. in re spouse to the movement of the pressplunger.

It is another object 01 the invention to provide a molding presscomprising valve means which is controlled by double'lever' systems, onelever of which efiect the shifting movement of said valve means inresponse to a predetermined point of travel of the press plunger, whilethe other lever oi said lever systems locks said first mentioned leverin its respective position and releases it only in response to apredetermined point of. travel of said press plunger.

It is a further object to provide a molding press which compriseshydraulically operable motor means for eflectlng an advancing and aretraction stroke of the press plunger, and'a hydrauli ing the mold,while mechanically controlled means is provided and adapted in responseto the movement of the press plunger selectively to effect or interrupthydraulic communication between said cylinder-piston-assembly and saidmotor means. I

It is another object of the invention to provide a molding press whichcomprises simplified means for selectively connecting or disconnecting adie to a die supporting member. ,7

Another object of the invention consists in the provision of a moldingpress having'a horizontally reciprocable die carrier, in which fluidoperable means for actuating said die carrier is arranged in the pressbed and may be removed therefrom as a. unit.

A still further object is to provide a molding press in which the moldis supported by yielding means adapted to be preloaded during themolding operation for retracting the mold to its initlal position.

It is a still further object of the invention to I according to theinvention.

vided tor filling the mold with molding material in response to theinitiation or a working cycle, and in which said means is automaticallymade, ineffective in case the material previously filled into th moldhas not been elected.

Still another object of the invention consists in the provision of amolding press with a measuring device for measuring of! and dispensing apredetermined charge into the mold, in which selectively one ora-plurality of measured charges may be unloaded into the mold beforestarting the molding operation. w i

It is another object to provide a molding press with a combinedmechanical and electrical control system, which may selectively beoperated with or without the electrical part" of said control system.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

Figure 1 illustrates a front view of the press Figure 2 is a side viewof the press shown in Figure l.

Figure 3 is a section along the line H of Fig. ure 1. a

Figure '4 is a section along the line 4-4 of Figure l.

Figure 5 is a sectionalong the line 5-6 of t," operablecylinder-pistoneassembly for liftto Figure 3 and shows. nar lrm cti a yrau c lifting means for the mold and the die carrier for the lower die.

Figure 6 shows a. detail of the shifting means for the die carrier.

Figure '7 is a view along the line 1-1 of Figure 6.

Figure 8 illustrates, partly in section, the press platen in connectionwith mechanical controllin means actuated thereby.

Figure 9 shows a part of trolling means of the press in differentdesignated 5, t, u, 'u, :c and 2.

Figures 10 and 11 show further mechanical con-- trolling means indifferent positions respectively designated a, b, c, d and m, n, o, p,q, r.

Figure 12 is a view along the line l2-l2 of Figure 10a.

Figure 13 is a view along the line l3--l3 of Figure 11122.

Figure 14 is a simplified wiring diagramfor the electric circuitassociated with the press according to the invention.

Figure 15 is a more elaborate wiring diagram corresponding to the wiringdiagram of Figure 14 but omitting the energizing circuit for the drivingmotor.

Figure 16 shws diagrammatically the filling of the mold prior to theinitiation of the molding stroke.

Figure 1'7 is a view similar to Figure 16 showing positions the initialphase of the molding stroke.

Figure 18 illustrates the molding plunger just prior to the beginning ofthe ejecting stroke.

Figure 19 shows the molding plunger at the end of its ejecting stroke.

Figure 20 is a diagrammatic illustration of the hydraulic circuit of thepress according to the invention.

Figure 21 is a graph illustrating the platen travel and the points ofoperation of the mechanical controlling means during the travel of theplaten.

the mechanical con-' Figure 22 is an energization chart of the varioussolenoids controlling the different operations during the pressingcycle.

General arrangement The hydraulic press according to the invention is avertical molding press having a main molding plunger with an upper dieand a movable mold with an opening at its bottom portion, which openingis adapted to be closed by a lower die.

The molding plunger' with the upper die, and the mold are movablevertically, whereas the lower die is movable horizontally so that thelatter may selectively release the opening at the mold bottom portion toallow the main plunger toeject the molded piece from the mold after thecompletion of a molding stroke.

Mechanical controlling elements are provided for timing the motions ofthe main molding plunger, the means for horizontally shifting the lowerdie, and the operation of the mold raising plungers, so that each willaccomplish its motion at the proper relative time.

The mechanical controlling means cooperate with electric means forcontrolling the supply of pressure fluid for actuation of the moldingplunger. This electric circuit is also arranged so that the press may becaused to operate selectively in semi-automatic or full automaticmanner, so that it respectively carries out one single molding cycle andthen stops, or performs a plurality of subsequent molding cycles.

Means is also provided for causing the press to accomplish alternatemolding and election strokes, wherein the molding plunger ismechanically controlled so that the ejection stroke thereof is shorterthan the molding stroke.

Furthermore, the press according to the invention comprises simplifiedmeans in the form of tapered connecting pins for connecting the upperand lower dies to the molding plunger and die carrier respectively,which means materially facilitate the exchange of the dies withouthaving ,to remove any other parts from the press.

According to a further feature of the invention, a hydraulicallyoperable cylinder-piston-assembly for shifting the lower die is arrangedwithin the press bed so that it can be removed therefrom as a unit.

STRUCTURAL ARRANGEMENT General arrangement Referring now to the drawingsin detail, the press comprises a press head l0 and a press bed I Iinterconnected with each other by strain rods l2. Reciprocably mountedin the press head In is a press ram l3 adapted to be actuated bypressure fluid supplied by a variable delivery pump H, which latter iscarried by a support l5 connected to the press head In.

The variable delivery pump comprises a shittable flow control member,the position of which, relative to a central pumping member, determinesthe delivery of the pump. Pumps of this type are well known in the artand for a more detailed description thereof reference may be had toPatent 2,159,553 to Ernst.

The press head also carries a fluid reservoir or surge tank 16.Operatively connected to the press ram I3 is a press plate l1 guided onguiding surfaces l8 and supporting a press plunger IS. The press plungerI9 has connected to the lower end thereof an upper die 20 (Figures 1 and4). The upper die 20 is provided with a protruding portion 2| engaging2. correspondingly recessed \portion 22 in the pressing plunger I9.

Threaded into the upper die 20 is a bolt 23 en gaging a correspondingbore 24 in the pressing plunger l9 and having a tapered bore 25 throughwhich passes a tapered bolt 26. The adjustment of the tapered bolt 26 iseffected by means of a nut 21 which is held in its respective positionby a lock nut 28.

Cooperating with the upper. die 20 and the pressing plunger i9 is a mold29 comprising a top portion 30, a lower portion 3| and an intermediateportion 32 interconnecting the upper and lower portions 30 and 3|.

The mold 29 is supported by a flange 33 of a movable mold support 34,which is slidable on the guiding surfaces I8. Relative angular movementbetween the mold 29 and the movable mold support 34 is prevented by akey 35 engaging the support 34 and the mold 29. The movable mold support34 has connected thereto two piston rods 36 with pistons 31 which arereciprocably mounted in cylinders 38 housing a spring 39 continuouslyurging the pistons 31 and, thereby, the mold 29 to their uppermostposition. The

movable mold support 34 is furthermore supported by and connected withtwo jacks generally designated 40, each of which comprises a fluidcylinder 4| and a. piston 42. v

The mold 23 has a slightly tapered bore 43 therethrough for receivingthe molding material, e. g., salt. The slight taper of the bore 43merely servesthe purpose of facilitating the ejection of the moldedpiece. The lower end of the bore 43 may selectively be closed by thelower di 49 which is connected to a die carrier 45 preferably in thesame manner as the upper die 20 to the pressing plunger. The die carrier45 is provided with a guiding flange 48 slidably movable in acorrespondingly shaped recess 4'! of the press bed (Figure 5). Alsoconnected to the die carrier 45 are two supporting blocks :294 (Figures3, 4, 16) which hold the mold 29 lifted and spaced from the die 48during the ejecting stroke of plunger l9 (Figures 18 and 19).

Detachably connected to'the die carrier 45, for instance by means ofscrews 48, is an arm 99, the lower end of which is fork shaped andstraddles a reduced portion 50 of a die carrier shifting plungergenerally designated 5|, one end 52 of which is reciprocably mounted ina cylinder 53, while the other end 54 of the shifting plunger 5| isreciprocably mounted in a cylinder 55. The cylinders 53 and 55 arerespectively connected with conduits 58 and 51. To prevent leakage fromthe cylinders 53 and 55, the ends thereof facing each other are providedwith packing material 59 compressed by glands 59. The other ends of thecylinders 53 and 55 have preferably mounted therein an adjustableabutment, such as a screw 53a and 55a adapted respectively to engage acorrespondingly shaped recess 52a and 54a. recesses and abutments alsoserves as cushioning means when the plunger 5| approaches one or theother end position.

Each of the cylinders 53, 55 is held in the press bed iiby means of asplit ring 69 (Figure 7) comprising two segment portions 6| and 52adapted to be composed to the ring 69. The segments BI and 82 have aflanged ring portion '93and 64 respectively, adapted'to engage anannular recess 95 in the cylinders 53 and 55.

The split ring 99 engages an annular recess 58 in the bed H and isconnected to the latter in any convenient manner, for instance by meansof screws 97. Angular displacement between the cylinders 53 and 55 andtheir respective split rings 90 is prevented by means of locating screws99. Also passing through the split ring 60 are two bolts 89 (Figure 6)threadedly engaging bolts 59, the ends of which pass through a plate itconnected to the bolts by means ofscrews 82. As will be clear from thedrawings, adjustment of the bolts 69 makes it possible to adjust theglands 59 in any desired manner.

To prevent molding material from falling into the space between thecylinders 53 and 55, an apron i3 is connected to the bed H in anyconvenient manner, and comprises a slot 14 through which passes the arm49.

A further apron l5, beneath the apron 13, is

connected in any convenient manner to the arm 49. The space between theaprons 13 and I5 is filled with a felt plate 16 connected to the apronl3 and-slidable on the apron 15, which latter has attached to its lowerside also a felt plate 11, adapted to slide on the bed plate 18.

The apron I5 is so dimensionedthat the slot 14 The cooperation of saidis always closed thereby, irrespectiveof the position of the arm 49;

The bed plate 18 has also connected therewith, for instance by screws19, the jacks 49. The piston rods 89 connected withthe jack piston 42have a sphe e e a in a correspondingly shaped wear plate 8| connected inany convenient manner, for instance by bolts the 'bed n.

82, to the movable mold support 34. The die carrier 45 has furthermoreconnected thereto an apron 83 which covers that portion of the guidingrecess 41 which is not engaged by the guiding flange 46. In this waysalt is likewise prevented from falling into the guiding recess 41.

Mechanical control for variable delivery pump nated. 81, which isconnected by a link system 88, 89' with the control rod 99 for the flowcontrol of the variable delivery pump |4.' The rod 94 has furthermoreadjustably connected thereto a collar 9| adapted to be engaged by aflange 92 of the sleeve 93 which is freely movable on the rod 84.

Slidably mounted on the sleeve 93 is a control member 94,- whichcomprises a yoke member 95 with an annular recess 98 corresponding indiameter to the diameter of the flange 92 but somewhat less in heightthan the said flange. The yoke member 95 has pivotally connected theretotwo arms 91, the upper ends of which are constantly urged toward eachother by, means of springs 98.

Furthermore connected to the rod 84 is a sleeve 99 with a flange adaptedto engage the bed H when the rod 84 is in its lowermost position. Theyoke member is connected by an arm |0| with the platen H. The controldevice of Figure 9 operates as follows:

Supposing the pump M has been placed into full stroke forward deliveryposition so that the platen i! now starts its downward stroke. The yokemember 95, due to its connection to the platen by arm |0|,' willlikewise start to move downwardly. Consequently, the push rod 84, due toits weight, will move from the position shown in Figure 9s downwardlyuntil its movement is stopped by engagement of .the flange Hill withWhen now th platen continues its downward movement, the yoke member 95will also continue its downward movement but since the push rod 84, dueto the engagement of the collar I99 with the bed H, has been stopped,the inner surfaces of the arms 91 slide over the collar 9| and relativethereto, thereby spreading, as shown in Figure 922.

Further downward movement of the platen I1 and yoke member 95 causes thearms ill-to pass below the collar 9| so that the springs 98 again ber ofFigure 9 has reached the position shown in Figure 9a. The pump 4 is nowreversed so as to cause the platen H to move upwardly.

Upward movement .of the platen I1 also causes the yoke member 95 tomove. upwardly. As a result thereof, the yoke member 95, after'apredetermined portion of the upward stroke has been completed, engagesthe flange 92 and carries it upwardly. A certain time thereafter theupper ends of the arms 91 engage the lower surface of the collar 9I sothat further upward movement of the platen and, thereby, of the yokemember'95 lifts the push rod 84. This lifting movement is conveyedthrough the lever 81 and links 88, 89, to the control rod 90 for thecontrol member of the pump I4, thereby causing the pump to move toneutral or no delivery position. The pump then comes to a halt, causingthe platen likewise to stop.

Figure 92) shows the position of the yoke member 95 and push rod 84shortly before the end of the partial retraction stroke, 1. e., when theplaten IT has reached the point 1) in Figure 21.

By means which will later be described, the pump I4 now is moved beyondneutral position to full delivery forward stroke position so that theplaten I! and thereby the yoke member 95 again start to move downwardly.Before the platen approaches its lowermost position, the flang I againengages the bed II and the sleeve 93 is again stopped by the sleeve 99.While the platen and thereby the yoke member 95 continue to movedownwardly, the inner surfaces of the arms 91 again slide over thecollar 9I and spread. However, in contrast to the movement from Figure915 position to Figure 9a position, the platen comes to a halt beforethe arms 91 can pass below the collar 9I.- The control mechanism thenoccupies the position shown in Figure 91:.

The pump I4 is now again reversed, thereby causing the platen to startits retraction stroke. As a result thereof, the yoke member 95 iscarried upwardly, but since this time the arms 91 are held in spreadposition until their upper ends have moved above the collar 9|, the arms9'! cannot engage the collar 9I. Consequently, the yoke member 95,together with the arm 91, performs a complete retraction stroke, incontrast to the partial retraction stroke illustrated in Figure 912.

Figure 92 shows the control member shortly before it has reached itsuppermost position. The various positions of Figure 9 are indicated inthe graph of Figure 21, illustrating the platen travel.

Hydraulic circuit Referring to Figure 20 diagrammatically illustratingthe hydraulic circuit of the press according to the invention, the presscylinder I02 is connected by means of a conduit I03 with one side of thevariable delivery pump I4, the other side of which is connected by meansof a conduit I04 with push back cylinders I05 having reciprocablymounted therein push back plungers I06 connected with the platen I! forperforming the retraction stroke of the platen. The platen I! hasconnected thereto ca-ms I01 and I08, of which the cam I01 is adapted tocontrol a levermechanism, generally designated I09,'

which in its turn controls the operation of a three-way valve I I0 ofstandard design.

The three-way valve H0 is connected with a conduit III leading to thepush back cylinders I05. A further conduit II2 connected with thethree-way valve IIO leads to the cylinders of the jacks 40, which areinterconnected with each other through the conduit H3. The third conduit4 connected with the three-way valve IIO communicates with a conduit'II5 comprising a check valve H8 and leading to the surge tank 76 with aconduit I'3I IS. The check valve 'IIB allows fluid to flow from theconduit II4 into the tank IE but not in the reverse direction.

To allow manual operation of the three-way valve III], the levermechanism I09 is connected with a member II'I continuously urged intothe position shown in Figure 20 by means of a spring II8, the lower endof which abuts the member II'I, whereas the upper end of the spring; II8contacts a stationary abutment H9. The member II! is connected with arod I20 passing through the spring H8 and connected with a cable I2Ipassing over rolers I22 and I23 and connected with an arm I24, one endof which is pivoted at I25, while the other end of the arm I24 isconnected with a handle I26. Conscquently, pulling the handle I26downwardly will compress the spring II8 for shifting t e lever mechanismHi9, thereby actuating the t ree-way valve III). The three-way valve IIOmaybe controlled so as selectively to effect or interrupt hydrauliccommunication between the push back cylinders I05 and the jacks 40.

The cam I08 is adapted to actuate a lever mechanism generally designatedI2'I, which controls a four-way valve I28 of standard design. Thefour-way valve I28 is connected with the conduit H5, and is furthermoreconnected with the conduits 58 and 51. A conduit I29 connected with thefour-way valve I 28 leads to an auxiliary pump I30, which may be of anydesired type, i. e., either a constant delivery pump or a variabledelivery pump.

The suction side of the pump I30 is connected leading to the tank I8.Mounted in the fluid tank I6 is a main cylinder release and pump by-passvalve I32, which is connected by means of a conduit I33 with a conduitI34 leading to the conduit I35, which latter is connected to the conduitI04. The conduit I35 which comprises a check valve I38 leads to thefluid tank I6. The check valve I38 allows fluid to pass from the tank I9to the conduit I04 but not in the reverse direction.

The conduit I34 comprises a pressure relief valve I31 for releasingexcessive pressure in the conduit I34 and is connected through a surgevalve I38. The surge valve I 38 is preferably of the type disclosed inPatent 2,193,248 to Ernst, and its main purpose consists in pre-fillingthe cylinder I02 when the press ram moves downwardly by gravity duringthe first portion of the working cycle. The valve I 32 is furthermoreconnected, by means of a conduit I39, with a conduit I40 comprising apressure relief valve HI and leading to the conduit I03.

The main cylinder release and pump by-pass valve 932 does not form apart of the present invention and for a more detailed descriptionthereof, reference may be had to U. S. patent application No. 286,063 toErnst, filed July 24, 1939. The purpose of the main cylinder release andpump. by-pass valve I32 consists in facilitating the initiation of theretraction stroke by releasing pressure from the main cylinder I02.

Also connected with the conduit I03 is a conduit I42 leading to atonnage control valve I43, which may be of any desired design,preferably of the type disclosed in Patent No. 2,224,957 to Ernst.

The lever mechanism I21 is continuously urged into the position shown inFigure 20 by a spring I44. -The valve I28 may, if desired, also beoperated manually by actuation of the handle I45, which is connected tothe cam arm I48- pivotally connected to a-support I41 carried by thefour-way valve I 28. The operation'of the four-way valve I28 controlsthe supply of pressure fluid to and the exhaust of pressure fluid fromthe die carrier shifting cylinders 53 and 55.

Automatic control of'three-way valve Referring to Figure 10, the camI01, connected from one position into another position without engagingthe surface I55. The arm I53 has a recess I56 which is adapted toreceive a pin I51 rigidly connected to the lever arm I50, therebypreventing further clockwise movement of the arm I53. The pivot pointI56 of the arm I 53 is so arranged that the arm I53 is urged by its ownI weight to rotate in clockwise direction.

The left end of the arm I 53, with regard to Figures and 12, iscontinuously engaged by the upper end of the stop member I55 carried bythe casing of the three-way valve III The valve member I55 of thethree-way valve die is pivotally connected to the arm I55 by means of apivot I55. The arm I55 has furthermore pivotally connected theretoa linkml, which in its turn is pivotally connected to the casing of thethree-way valve H0. The control mechanism of Figure 10 operates asfollows:

Supposing that the platen I1, and thereby the cam I01, is movingdownwardly, starting from Figure 10a position, the slant surface I 52,which in Figure 10a position engages the roller I69, will first move thesaid roller downwardly, thereby shifting the lever arm-I5Iiin clockwisedirection about the pivot I60 so that the valve member I55 willbe moveddownwardly. When the arm I50 during this shifting movement has reached apredetermined point, the roller I59 engages the cam. surface I58 androlls on this cam surface. during the further downward movement of theplaten I1. I

Since the left upper surfaceof the lever arm I56 is prevented frommoving upwardly by the stop member I56, the shifting movement of the armI50 causes the roller I52 to move downwardly until the pin I51 carriedby the arm I56 is fully received by the recess I56 of the lever arm I53.This position is shown in Figure 10b, from which it will be noted thatthe roller I52 just engages the cam surface I5I while the roller I isstill in engagement with the cam surface I45. By means later to bedescribed, the movement of the platen is now reversed so that it movesupwardly.

Since now the arm I53, due to the engagewhile in the first two phases,Figures 10a and 10b, the lever arm I moved the arm I53 into position.When the platen I1 now continues its upward movement and has reached apredetermined position, the cam surface I5I finally disengages theroller I52 so that the spring II8 (Figure 20). shifts both arms I50 andI53 in anticlockwise direction, thereby returning the sanie to theiriniti ,1 position as shown in Figure 10d.

Automatic control of four-way valve Referring to Figure 11, the cam I00carried by the platen I1 comprises a cam surface I66 located in the sameplane as and adapted to cooperate with the roller I64 rotatablysupported by the arm I65 which, by means of pivot I56, is pivoted to thelever arm I61 of the lever mechanism I21. The cam I08 furthermorecomprises a cam surface I66 located in the same plane as and adapted tocooperate with the roller I69 rotatably supported by the lever arm I10,which latter is pivotally connected to the lever arm I61 likewise bymeans of the pivot I55.

Each of the arms I65, I10 has, at one endthereof, a recess I II, I12,respectively adapted to engage correspondingly shaped abutments I15 andI16 (Figure 13). The lever arm I51 is pivotally connected to a link I15which in its turn is pivotally connected by means of the supporting armI I5 to the casing of the four-way valve I28. The arm I6? is furthermorepivotally connected by means of the pivot I11 to the valve plunger I15.The control device of Figure 11 operates in the following manner:

ment of its roller I52 with the cam surface I5I,

cannot shift in anti-clockwise direction, it maintains the positionshown in Figure 10b and, due

to its connection with the arm I50, also forces the latter to remain inthe position shown in Figure 10b. However, since the platen I1 movesupwardly, the oam surface I48 'disengages the roller I49. The device'isthen in the position of Figure 100. It will be noted that in thisposition the arm I53 holds the lever arm I50 in position,

Supposing that the platen I1, the cam I58 and the lever mechanism I21are in the position of Figure 11m, and that the platen I1 now starts adownward stroke. Downward movement of the platen also causes a downwardmovement of the cam its so that the slant cam surface I15, due to itsen'gagement with the roller I6 3, shifts the latter about the pivot I65so that it will engage the cam surface I 63. When the lever arm I65 hasbeen so moved, it disengages the abutment Furthermore, movement of thecam I58 has, at this time, brought the cam surface I into engagementwith the roller I69 and, thereby,'

shifted the lever arm I15 likewise about the pivot I65. The levermechanism I21 then occupies the position, of Figure 1112. The pivot I isso arranged with regard to the lever arms I65 and I10 that the saidarms, by their own weight, tend to rotate in clockwise direction.

Further downward movement of the platen I1 causes the roller I-65 todisengage the cam surface I 66 and to return into its horizontalposition as shown in Figure 110, while the roller I64 engages the camsurface I63. When the platen is now reversed, the cam surface I66 againengages the roller I69 but this shifts the same upwardly and, since thearm I10 engages the abutment I14, it also causes the lever arm I61 toshift in clockwise direction about the pivot I11. This shifting movementof-the lever arm I61 moves the valve plunger I18 to its lowermostposition.

The last mentioned shifting movement of the leverarm I61 carries the armI65 upwardly but while the roller I 64' in this uppermost position inFigure 11p does-not yet engage the cam surface I63, the roller I69engages the cam surface I60. If now the platen I1 is again moveddownwardly, the roller I64 comes into engagement with the cam surfaceI63, thereby maintaining the lever arm I61 so shifted that the valveplunger I18 stays in its lowermost position. However, the roller I69disengages the cam surface I68 but still remains in its previouspositlon. The control system then occupies the position of Figure llq.

If the platen I1 now moves upwardly, the cam surface I68 will merelypass beneath the roller I69 without causing any change in the positionof the levers, and when the cam surface I68 has passed beyond the rollerI69, the lever arms I65 and I are free to return to their horizontalposition and are so returned by means of the spring I44. The controlmechanism then occupies the position of Figure 111'.

The different positions of the control mechanisms of Figures 10 and 11are also indicated in the graph of Figure 21.

Electric circuit Referring to Figure 15, I80 and I8I designate the mainsupply lines. Connected with the main supply line I80 is a switch armI82 adapted when in closed osition to contact the terminal I83 which isconnected to the line I84. Also connected with the line I84 is anormally closed cycle stop switch I85 which in its turn is connectedwith the solenoid I86. The solenoid I86 is connected by line I81 withthe normally closed tonnage control switch I88 provided in the tonnagecontrol valve I43 and connected to the main supply line I8I. Alsoconnected with one end of the solenoid I86 is a line I89 adapted to beconnected by aswitch blade I90 with the pump solenoid I9I, theenergizatlon of controls the movement of the pump I4 to full deliveryforward stroke position.

The operation of the switch blade l90 is con trolled by the solenoidI92, one end of which is connected with the pump solenoid I9I and themain supply line I8I by line I93. The other end of the solenoid I92 isconnected to a, line I94 adapted to be connected with the line I95 bymeans of the switch blade I96. The line I95 is adapted to be connectedby means of the die limit switch blade I91 with the line I98 connectedto the line I99 by the normally closed switch blade- 200. The die limitswitch blade I91 is opened when the lower die 44 is in alignment withthe mold bore 43. This opening is efiected by a cam 226 (Figure 16). Theline I99 is adapted to be connected with the line 20I by means of theswitch blade 202. The line 20I comprises a normally closed ram switch203 and leads to the line I89. The solenoid I86 controls,

which which latter is connected into alignment with the mold bore 43, i.e., is moving from the position of Figure 19 to the position of Figure16.

The line I89 leads to the solenoid valve 22I, by means or line 222 to a,line 223 adapted by closure of the switch blade 224 to be connected withthe line 225 leading to the main supply line I8I.

Connected with the line I81 is a line 221 leading to one end-of thesolenoid 228, the other end of which is connected to a line 229. Thesolenoid 228 controls the normally open switch blades 230, 23I and thenormally closed switch blade 232. The switch blade 230 controls theinterconnection of lines I84 and 233, the latter of which is connectedto the line 234 leading to the terminal 235. The terminal 235 may beconnected with the terminal 236 connected to the in addition to theswitch blade I96, the switch blade 204 adapted to interconnect the line205 with the line 201 which comprises a normally I closed switch 285 andis connected to one end of the solenoid 208, the other end of. which isconnected by line 209 with the mainsupply line I8I. Also connected ,withthe main supply line MI is a line 2I0 adapted-ate be connected by meansof the switchjblade 2H with-the line 2I2 leading to a timer:2;t3.;-;Thezswitch blade 2I.I is controlled by .thezsplenoid-208gwhichalso controls the switch-blades m 216.25. -Cl0sure. of the switch bladefldi intercd nects the line 2I6 leading to the line 2-l1-,with the line205.

Also connected with the of a solenoid 2I8, the other end of which isconnected to a line 2 I9 adapted to be connected with the line I89 byclosure of the normally open switch blade 220. The switch blade 220 isclosed by the cam 226, while the lower die 44 is moved line I84.

The cycle start switch is designated 231 and when in closed position isadapted to connect the line 238 withthe line 239 leading to one end ofthe solenoid 240. The other end of the solenoid 240 is connected withthe switch arm 24I adapted selectively to be connected with the line 242or line 243, depending on whether full automatic or semi-automaticoperation is desired.

The line 243 is connected with a line 244 by the normally closed switchblade 245. The line 244 is connected to the line 246 which, on one hand,leads to the main supply line I8I and, on the other hand, is connectedto one end of the solenoid 241. The other end of the solenoid 241 isconnected to a line 248 adapted to be connected with the line 249 byclosure or the switch blade 250. The line 249 which leads to the linei89 is adapted to be connected by means of the switch blade 25I with theline 252 which in its tum may be connected with the line 248 by closureof the switch blade 253. The solenoid 241 controls, in addition to theblades 200, 245 and 253, also the normally closed switch blade 254. Theswitch blade 254, when closed, connects the lines 228 and 234.

Also connected with the line I89 is a line 255 adapted by closure of theswitch blade 256 to be connected with the line 208 leading to the line205.

The numeral 251 designates a solenoid having one end thereof connectedto the line 258 which leads to line 242, while the other end oi thesolenoid 251 is connected to a line 259 comprising limit switches 260,26I, 262 and 263. The limit switch 260 is normally closed when the scaleis full, while the limit switch 26! is normally closed when the lowerdie 44 is in alignment with the mold bore 43. The limit switch 262 isnormally closed when the mold is in its lowermost position, and thelimit switch 263 is normally closed when the press plunger I9 is in itsuppermostposition (Figure 16).

The line 259 is normally connected with the line 264 through thenormally closed switch blade 232. The line 264 is connected through thenormally closed switch blade 2I5 with the line 265 which in its turn maybe connected to the line 266 by closure of the switch blade 261 which iscontrolled by the solenoid 240. The line 266 is connected to the line238, which latter may be connected with the line 239 by closure ofswitch blade 266.

The solenoid 251 controls switch blade 269 which isadapted, when toconnect the line 210 with the line 21I conthe normally open closed, I

nested in its turn with one terminal of each of the switches 260 and26!.

Connected with the line I98 is a line 212 adapted by closure of theswitch blade 213 to be connected with line 214 which leads to the lineI95.

The detailed electric circuit of Figure 15 is illustrated in asimplified diagram in Figure 14,

in which the corresponding parts are designated Eneryz'zation chart.

The chart of Figure 22 has plotted as ordinates the travel of the platenI1 and the numbers of the electric control solenoids, whereas the timeof travel of the platen I1 and the period of energization of the saidsolenoids are plotted as abscissae.

By consulting this chart, it is possible imme-' diately to determine thestate of energization of all solenoids at any random point of travel ofthe platen.

Supposing it is desired to find out which solenoids are energized andwhich solenoids are not energized at the position IV of the platen, i.e., at the position when the platen is just beginning to start the firstdownward stroke of a cycle. Following the vertical line downwardly fromposition IV, it will 'be noted that this vertical line cuts through thehorizontal 'energization lines pertaining to the solenoids I86, 240 and208, which indicates that these solenoids were already energized priorto the position IV and still remain energized.

The said vertical line furthermore touches the beginning of thehorizontal energization lines pertaining to solenoids I92, Isl, whichindicates that at this time the solenoids I3l and I82 have just beenenergized.

Since the energization lines pertaining to the solenoids 251, 241 and2|! are not crossed nor touched by the said vertical line, the solenoids251, 241 and 2l8 are not energized in the position IV of the platen.

To sum up the situation, a glance at the chart of Figure 22 shows thatat the position IV of theplaten I1, the solenoids I86, 240, 200, I32 andISI are energized, whereas the solenoids 251, 241 and 2I8 are notenergized.

Similarly, examining the situation when the platen is in the position V,i. e., is about to start its partial retraction stroke, it will be notedthat the solenoids Isl, I92 and 208 have just reached the end of theirenergizationperiod, in other words, are now deenergized, whereas thesolenoid 240 is still energized. The chart also indicates that at theposition V the solenoid I86 reaches the end of one energization periodand immediately thereafter starts a new energization period. This lastmentioned feature is due to the fact that the tonnage control switch I8818 open for a very short time and closes immediately after the pressurein the press cylinder I02.decreases.

In addition to the solenoids just mentioned, the

chart also indicates that at the position of Figure 50f the platen, thesolenoids 251, 241' and 2I8- are not energized.

It will also be noted that the chart of Figure 22 indicates at a glanceduring which period of time of travel of the platen. or between whichpoints of travel of the platen, the various solenoids are energized andnot energized respectively. For instance, considering solenoid I92, it

will be noted that this solenoid is energized when the platen starts itsfirst downward stroke during a cycle, i. e., in position IV, and thenstays energized until the platen has reached the position IV, i. e., isabout to start its partial retraction stroke.

Semi-automatic operation The operation of the press will be bestunderstood in connection with Figures 2-1 and 22, of which Figure 21shows the points at which, during the travel of the platen, the variousmechanical controlling means are actuated, while Figure 22 shows atwhich points of the travel of the platen the electric controlsolenoids'are actuated.

Assuming now that the press is in the position of Figure 12 with theautomatic control for the three-way valve I I0 in the position of Figure10a and the automatic control for the fourway valve I28 in the positionof Figure 11m;

"assuming further that the mechanical control words, to start th pressfor semi-automatic operation. I 4

To this end the operator shifts the switch arm 2" so as to cause thelatter to interconnect the solenoid 240 with the line 243. then startsthe auxiliary 'pump' I30 and closes the switch 280 (Figure.14).-to,start the 'motor driving the pump I4. Thereafter the'operatormoves the switch arm I32into closed position (Figure. 15) andfurthermore closes the cycle start switch 231. e

This will cause current to flow from the main supply line I throughswitch arm I82, cycle stop switch I85, solenoid I86, line I81, tonnagecontrol switch I88 and main supply line I8I.

As a result thereof the solenoid I86 is energized" supply line I80through the switch arm I82, the 1 cycle stop switch I85, line I88,closed cycle start switch 231, solenoid 240, line 243, switch blade 245,lines 244 and 248 and the main supply line I8I. As a result thereofthersolenoid 240 is energized and causes the switch blades 268, 261

and 202 to move into closing position. Closure of the switch blade 268establishes a holding cir.

cuit for the solenoid 240, which holding circuit comprises the mainsupply line I80, cycle stop.

switch I85, line l89, line 238, switch blade 268, solenoid 240, switcharm 24 I, line 243, the normally closed switch blade 245, line 24-4 andline The operator 284, closed switch blade 232, line 259, now closedlimit switches 263, 262, 26I, 260, solenoid 251, 7

which is shiftable about the stationary pivot 211.

Tripping of the scale 215 by the solenoid 251 allows the salt to flowfrom the scale through the chute 216 into the mold 29. When thescale 215is about empty, the weight 218, by means of the linkage 219 connected tothe chute 216, shifts the latter into Figure 16 position. This movementcauses the switch blade 260 to open which, however, does not affect theenergization of the solenoid 251 since the switch blade 260 is by-passedby the line 21I. Furthermore, due to the said movement, the weight 218closes. the switch blade 256.

Closure of the switch blade 256 establishes a circuit comprising themain supply line I80, cycle stop switch I85, lines I89 and 255, blade256, lines 206 and 205, now closed blade 204, line 201, solenoid 208,line 209 and main supply line I8I.

This circuit energizes the solenoid 208 so that switch blades 2| I and2I4 move into closing position whereas the switch blade 2I5 opens.Opening of the switch blade 2I5 breaks the energizing circuit for thescale tripping solenoid 251 so that the switch blade 269 opens. Closureof the switch blade 2I4 establishes a holding circuit for the solenoid208, which holding circuit comprises the main supply line I80, switcharm I82, cycle stop switch -I85, line I89, lines Zn and 2I6, switchblade 2, line 205, now closed blade 204, line 201, solenoid 208, line209 and main supply line I8I.

Closure of the switch blade 2 closes the energizing circuit for thetimer 2I3, which circuit comprises main supply line I80, switch arm I82,cycle stop switch I85, line I89, line 2I1, timer 2I3, line 2I2, switchblade 2I I, line 2I0 and main supply line I8I.

At the end of the time for which the timer 2 I3 has been set, the timerswitch blade 213 is closed. This establishes a circuit comprising themain supply line I80, switch arm I82, line I89, ram switch 203, the nowclosed switch blade 202, line I99, switch blade 200,-1iries I98 and 212,timer switch blade 213, lines 214 and I95, now closed switch blade I96,line I94, solenoid I92, line I93 and main supply line I 8|.

Energization oi the solenoid I92- causes the switch blade I90. to close,thereby 'closi'ng the energizing circuit for the pump solenoid I 9I,which circuit comprises the main supply line I80, switch arm I82, cyclestop switch I85, line I 89, switch blade I90, pump solenoid I9I, line,I93 and main supply line I8I. Energization of the pump solenoid I9Iactuates, by means of the linkuse 88, 89 (Figures 9 and 20), the flowcontrol member of the pump I4 so as to shift the'latter to full deliveryforward stroke position? I Pressure fluid is now delivered by the pumpI4 through the conduit 103 into the upper portion of the press cylinderI02, while fluid is withdrawn from the push back cylinders I08 throughthe conduit I04 to the suction side of the Pump I4. The press ram I3 nowmoves downwardly by gravity and-the! fluid delivered by the pump I4through the conduit I03 into the press cylinder I02 is supplemented byfluid from the fluid tank I6, which fluid passes throush the surge valveI38. While the ram I3 and the pressing plunger I9 connected thereto aremoving downwardly, the switch blade 263 opens and the scale 215 is againfilled with salt. When the scale is completely filled, it overcomes theweight 218 so that the chute supporting the scale moves from theposition of Figure 16 into the position of Figure 17, thereby openingthe switch blade 256. Opening of the switch blade 256 deenergizes thesolenoid 208, thereby breaking the energizing circuit for the timer 2I3.As a result thereof the timer switch blade 213 opens and the timer isreset.

When the pressing plunger I9 during its downward movement has reachedthe position of Figurel'l, it has already partially compressed the saltin the mold, which latter, due to the friction between the salt and themold, has likewise been moved downwardly against the thrust of thespring 39, which previously held the mold in its normal upper or idleposition. The downward movement of the mold 29 also expels fluid fromthe jacks 40 through the conduit II2, the threeway valve IIO, theconduit H4 and the conduit II5 into the tank I6 until the platen I1 hasreached the point indicated 1) in the graph illustrated in Figure 21.When the pressing plunger I9 engages the salt in the mold, pressurebuilds up in the press cylinder I02 and the surge valve I38 closes.

When the platen I1 has moved from the position a to the position b inFigure 21, the cam I01 of the platen I1 has shifted the three-way valveIIO from Figure 10a position into Figure 10b position in the mannerpreviously described under "Automatic control of three-way valve. Thisshifting movement of the three-way valve IIO breaks the connectionbetween the conduit H2 and the conduit H5 and establishes hydraulicconnection between the conduit I I2 and the conduit III connected to thepush back cylinders I05. The jacks 40 and the push back cylinders I05then remain interconnected during the present downward stroke of theplaten I1. During the same downward stroke, the four-way valve I28 staysin the position shown in Figure 20, in which fluid pressure from thepump I30 is conveyed through conduit I29, four-way valve I 28' andconduit 51 into the die carrier shifting cylinder 55, while the four-wayvalve I28 simultaneously interconnects the conduit 56 connected with thedie carriershifting cylinder 53 with the exhaust line II5.

During this downward stroke of the platen I1 which is illustrated bythe'portions s-t-a-b-mn-u in the graph of Figure 21, the push or controlrod 84 moves from Figure 9s position into Figure 9a position, in themanner previously described under Mechanical control for variabledelivery pump.

When the salt has been compressed to a desired extent, apredeterminedpressure has built up in the press cylinder I02, which pressure isconveyed through the conduits I03 and I42 to the tonnage control valveI43 so that the tonnage control switch I88 opens. Opening oi! thetonnage control switch I88 breaks the energizing circuit for thesolenoid I86 so that the switch blades 204 and I96 open.

Opening of the blade I98 breaks the energizin circuit for the solenoidI92 so that also the blade I98 opens, which latter breaks the energizingcircuit for the pump solenoid I9I. As a result thereof a spring in thepump I4 shifts the 'pump to full delivery retraction stroke position sothat pressure fluid is now passed through conduit I04

